L2000 wiring problem. Paging Ken Baker, Spidey, etc.

If you're the original owner, check your warranty status.

That's just plain weird. Assuming that the thing was wired correctly, there's no way for the treble control to only work in parallel mode. The tone and volume controls are completely downstream from the pickups and their switching.

Part of me would say that you've got a failed coil. However, considering what you've said about the treble control, all bets are off until the coil is isolated and checked. I'd completely disconnect the pickups from the series/parallel switch and measure the DC resistance of each coil in ohms. All four coils should be essentially equal. Any value that is notably off would be suspect. If the coil is indeed dead, you can either replace the whole pickup or have it repaired. I'd call some good pickup people before I'd replace it.

How solder connections look and how they well work can be different; cold solder joints like to hide. You could also have a conductor broken inside its insulation and not even see it, though you could feel it by wiggling the wire long its length.

At this point, I wouldn't trust anything. Download and print my wiring diagram and use it to "proof" the wiring in your bass. Alternately, you can use it to completely re-wire your bass if you'd like. If the wiring looks okay, you might heat up the connections to reset them.

Could be a failed or failing chip on the preamp board. Could also be a thoroughly mucked up jack. Does this happen if you pull the battery? How about if you pull the chip (it's socketed)? If the "fuzz" problem persists with either or both pulled, the jack becomes suspect.

Sadly, this isn't atypical. I'd recommend that you post your customer service experience at Guitars By Leo. You might get their attention by posting at a location where a little bit of attention is paid (this ain't it). I'm not a G&L employee, so I can't do anything more than raise the same sort of ruckus that you can raise.

That's a good thing! At least so long as you don't use some great big ol' soldering gun!

Ken...

 

I knew that....

The G&L warranty is to the original purchaser. They've been known to fudge on that, but there's no way of knowing when or if.

If you don't have one already, buy a simple multimeter, either analog or digital. This is the tool to use for measuring the DC resistance of the pickup coils. The instructions will give you the basics on use. You'd then connect the meter to the black and white leads of a pickup and see how it reads. Then the green and yellow leads. Repeat for the other pickup. All the measurements should match or be very close.

To do it properly, the pickups should be removed, or isolated, from the rest of the circuit. While "Guitar O.R." may be able to do that, you can as well.

Give G&L another jiggle and see if they grunt. If no response, dig in.

Ken...

 

Yup. They used to be called Volt-Ohm Meters, or VOMs, a few years ago. Now it's multimeter. They are more capable than a simple circuit tester, though there are limits. Do read the instructions.

As much a pain as it is, and as much a pain as G&L can sometimes be to wake up, I'd still recommend that you explore the warranty route. The USA basses come with a 10 year warranty. Unless the warranty has specific language for Canada, you should be covered.

You should understand that digging around in the cavity doing your own repair could void the warranty. G&L is usually pretty flexible, but there are limits.

The control cavity of an L series G&L is a pretty tough learning ground, but you'll probably be okay if you go slow and be careful. You might also do well to keep it stock at least for a while. Those long leads are a pain, but kind of necessary due to the non-modular way that G&L builds the circuit, so don't shorten them unless you actually know that you can do it and still be able to re-assemble things.

Never sand down a solder connection, as you don't want any of the abrasive or filings/dust in the cavity (you'll never get it all out). Buy some de-soldering braid and learn how to use it by practicing on something else. A de-soldering bulb might also be helpful.

It is very likely that the only things you'll need to test for continuity/conductivity are the pickups as noted earlier.

The interior of the cavity should already be shielded with shielding paint; that dark gray stuff. The electronics will be automatically connected to it when the pots are tightened, so there's nothing special to do there. There is a wire running from the bridge to the cavity and it should be connected to ground, so no worries there.

Thanks, but I'm no king. And please remember that I am, in no way, speaking for G&L.

For anyone reading this that would like to dive into their bass but have no clue about soldering (be honest!), give this page a read. De-soldering isn't covered, but maybe the author can be coaxed.

Ken...

 

I understand completely. I could have taken a bridge issue to them on my L-2500 (stripped screws), but elected to fix/mod it myself for that very reason. It would only take me about 20 minutes to drive to the BBE office...

Okay. The copper braid is probably all you'll need, especially if it's the fine-weaved stuff.

Try this:


http://www.bassesbyleo.com/images/l2500/modded/stuffed_cavity.jpg

It actually makes more sense than the stock wiring if the OBP-3 block is lifted out of the cavity, but there are still a lot of wires in there. The only wires remaining from the original are the pickup leads and they were not shortened for the project.

Cool, and thanks for your understanding. I'm glad to help where I can, but it's only me doing it.

Heh... I doubt that would happen, but thanks for the kind words.

Ken...

 

Bass/treble, which is, more-or-less, the norm for such things. Mid is a separate pot. I have it hardwired for low-mid control.

What you see there is the DavePlaysBass single coil mod, providing series/single (outers)/parallel modes. EQ is 3-band, fully active boost/cut. Active/passive switch is just that. No EQ on passive. The entire package is a combination on Dave's and Aguilar's circuits.

Works well, sounds huge, don't do it until/unless you get the current bugs worked out. Then you'll be at a known place.

More.

Ken...

 

0 as in 0 ohms (shorted coil) or no reading at all (open coil). Sounds like new pickup time.

Disconnect the bad pickup from the circuit and see what happens to your tone problems.

Jim

 

Were the pickups, particularly the one in question, isolated from the switch? Meaning that all four leads were disconnected? It's important that they were so that the readings you're getting are accurate.

I'm not so concerned with the pickup that appears to be good. With respect to the other pickup; it is possible that a shorted switch can cause a coil to appear to be shorted when it really isn't. This is why it's important to have it out of circuit.

If the pickup was disconnected when you did the test, and assuming that the 0 you read meant zero ohms (a dead short), then replacement is the best way to go because shorts are very difficult to find. It the zero was your meter's way of expressing infinite ohms (open circuit), then repair may be possible because a lot of breaks are near the surface of the overall coil or at the lead connections.

Ken...

 

If this is the bad coil you're talking about, this would indicate that it's open.

Meter geek stuff:

An ohmmeter sends a small, known, amount of voltage through a circuit and measures it. It compares what it knows it sends with what it's reading. The difference is then calculated and displayed as resistance in ohms.

In an open circuit - one that is broken - voltage is sent but no voltage is measured, so the meter reads it as infinite resistance to voltage flow because no voltage is flowing.

In a shorted circuit, all the voltage sent is measured and the meter reads it as zero (0) ohms of resistance because all the voltage is flowing.

So...

If your coil is measuring zero (0) ohms, it's shorted someplace close to the leads. If your coil is measuring infinite resistance, it's an open coil with a break somewhere.

Either way, it's a repair/replace deal for you. Go with whatever is easier.

Ken...

 

Open coil.

Put in the good one and see if that is your only problem.

That would have caused issues whenever running that pickup or both in series.

Less so in parallel.

Jim

 

Up to you. I certainly wouldn't bother putting the bad one back in circuit.

Very cool. On something like that, where you're just sending in a part to swap, it should be quick. I'll keep my fingers crossed.

Ken...

 

The pickups are identical so slap that good one back in and see if the bass fully functions with that one installed.

You found a problem with that open coil but see if that was the cause of your woes.

Jim